520 FOOTE— FACTORS IN THE [April 25, 



negligible in an estimate of available exchange material. He con- 

 cluded his review with a conditional acceptance of the exchange 

 basis established by Wiilfing, and welcomed his guidance among 

 those final personal factors which in the past have rendered meteorite 

 exchanging so difficult a process. 



In 1904 the late Professor Henry A. Ward, the greatest traveling 

 collector of meteorites, made a new collation^ of seven dealers' 

 prices, contrasting his results with those of Cohen. Professor Ward 

 included the prices paid at a large meteorite auction, as well as two 

 records of many sales, but excluded all abnormal figures. He was 

 the first to fully emphasize the fact that a large specimen is worth 

 far less per gram than a small one of the same fall. However, 

 he greatly overestimated this variation in saying, in efifect, that an 

 increase of sixteen-fold in weight deserved a decrease to one eighth 

 the gram price. This would make a 16-pound piece worth only 

 twice as much as a i -pound piece of the same fall. 



Present Factors. — In using the Ward Collation, the writer, in 

 common with most exchangers, found it of great value, but as often 

 lacking because of the numerous meteorites commercially quoted 

 during the intervening eight years. In making a 1912 collation for 

 personal use, it seemed worth while to check it carefully throughout 

 and publish with certain observations. 



The following arrangement of the main elements of meteorite 

 values, attempts only to roughly indicate the order of their im- 

 portance. The first factor may make a difference of several hun- 

 dred-fold in the gram price, the second usually five to ten-fold, and 

 rarely much more. The remaining factors generally involve lesser 

 variations. 



Essential Factors. 



1. Present known weight. 



2. Weight of specimen offered. 



3. Number of owners. 



4. Group weight. 



5. Observation of fall. 



s " Values of Meteorites : Relative and Individual," The Mineral Collector, 

 Vol. XL, No. 7, pp. 97-115, New York. 



